Computational fluid dynamics assessment for the thermal performance of double-skin façades in office buildings under hot climatic condition

2020 ◽  
Vol 42 (1) ◽  
pp. 45-61
Author(s):  
Daeung Danny Kim

In general, a double-skin façade has been used to reduce energy consumption as well as to improve thermal performance in buildings as a buffer space between indoors and outdoors. The goal of this study is to undertake pre-normative research to provide information for developing a comprehensive double-skin façade system under the climatic condition in Saudi Arabia. To pursue this goal, the characteristics associated with the double-skin façade system are identified. In addition, the impact of various configurations on the thermal performance of the double-skin façades is evaluated under the weather situation in Saudi Arabia. Computational double-skin façade models are created by computational fluid dnamics simulation to assess the thermal performance of the various configurations such as cavity geometry and the use of a shading device. As a result, the variation of the opening size has a significant impact on the temperature in the cavity of the double-skin façade. For the air velocity in the cavity, the variation of the opening size and cavity depth is less sensitive. Moreover, the use of a shading device has an impact on the temperature drop in the cavity of the double-skin façade. Practical application: Generally, many studies have investigated the efficiency of double-skin façade applications due to its beneficial aspects. However, a few buildings have adopted double-skin façades to their envelopes. With a substantial growing demand for building industry in Saudi Arabia, double-skin façade applications to building design can be a solution for reducing building energy consumption. The present study investigates the thermal performance of double-skin façades under hot climates in Saudi Arabia and it can provide information for building stakeholders to develop proper double-skin façade systems

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Md. Jewel Rana ◽  
Md. Rakibul Hasan ◽  
Md. Habibur Rahman Sobuz

PurposeApplication of appropriate shading device strategies in buildings can reduce direct solar heat gain through windows as well as optimize cooling and artificial lighting load. This study investigates the impact of common shading devices such as overhangs, fins, horizontal blinds, vertical blinds and drapes on energy consumption of an office building and suggests energy efficient shading device strategies in the contexts of unique Bangladeshi subtropical monsoon climate.Design/methodology/approachThis research was performed through the energy simulation perspective of a prototype office building using a validated building energy simulation tool eQUEST. Around 100 simulation patterns were created considering various types of shading devices and building orientations. The simulation results were analysed comprehensively to find out energy-efficient shading device strategies.FindingsOptimum overhang and fin height is equal to half of the window height in the context of the subtropical climate of Bangladesh. South and West are the most vulnerable orientations, and application of shading devices on these two orientations shows the highest reduction of cooling load and the lowest increment of lighting load. An existing building was able to save approximately 7.05% annual energy consumption by applying the shading device strategies that were suggested by this study.Originality/valueThe shading device strategies of this study can be incorporated into the Bangladesh National Building Code (BNBC) as new energy-efficient building design strategies because the BNBC does not have any codes or regulations regarding energy-efficient shading device. It can also be used as energy-efficient shading device strategies to other Southeast Asian countries with similar climatic contexts of Bangladesh.


Author(s):  
Nimra Kanwal ◽  
Nuhzat Khan

Buildings are the most important part of development activities, consumed over one-thirds of the global energy. Household used the maximum energy around the world, likewise in Pakistan residential buildings consumed about half of total energy (45.9% per year). The study aims to analyze the impact of building design on climate of Metropolitan City Karachi, Pakistan and to evaluate the change in urbanization patterns and energy consumption in the buildings. To have better understanding of the issues correlations was established amongst population, urbanization patterns, green area, number of buildings (residential and commercial), building design, energy consumption and metrological records (climate change parameters) by collecting the data from the respective departments. With the help of the collected data amount of carbon dioxide was estimated. The results reveled that during last 36 years the urban population of Karachi increased exponentially from 5,208,000 (1981) to 14,737,257 (2017) with increase in urbanized area from 8.35 km2 (1946) to 3,640 km2 (2017) that may led to reduce the green area of the city from 495,000 hectors (1971) to 100,000 hectors (2015). Moreover, the building’s design and numbers are being changed from 21 high-rise buildings (2009) to 344 (2017). It may be concluded that change in temperature pattern and climatic variability of the city may be due to increase in population and change in lifestyle that lead to high energy consumption that is prime source of increased in CO2 emission in the environment of Karachi city, However, Greenhouse Gases (GHG) releases are much lower than the levels reported from metropolitan cities around the world.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amneh Hamida ◽  
Abdulsalam Alsudairi ◽  
Khalid Alshaibani ◽  
Othman Alshamrani

PurposeBuildings are responsible for the consumption of around 40% of energy in the world and account for one-third of greenhouses gas emissions. In Saudi Arabia, residential buildings consume half of total energy among other building sectors. This study aims to explore the impact of sixteen envelope variables on the operational and embodied carbon of a typical Saudi house with over 20 years of operation.Design/methodology/approachA simulation approach has been adopted to examine the effects of envelope variables including external wall type, roof type, glazing type, window to wall ratio (WWR) and shading device. To model the building and define the envelope materials and quantify the annual energy consumption, DesignBuilder software was used. Following modelling, operational carbon was calculated. A “cradle-to-gate” approach was adopted to assess embodied carbon during the production of materials for the envelope variables based on the Inventory of Carbon Energy database.FindingsThe results showed that operational carbon represented 90% of total life cycle carbon, whilst embodied carbon accounted for 10%. The sensitivity analysis revealed that 25% WWR contributes to a significant increase in operational carbon by 47.4%. Additionally, the efficient block wall with marble has a major embodiment of carbon greater than the base case by 10.7%.Research limitations/implicationsThis study is a contribution to the field of calculating the embodied and operational carbon emissions of a residential unit. Besides, it provides an examination of the impact of each envelope variable on both embodied and operational carbon. This study is limited by the impact of sixteen envelope variables on the embodied as well as operational carbon.Originality/valueThis study is the first attempt on investigating the effects of envelop variables on carbon footprint for residential buildings in Saudi Arabia.


2020 ◽  
Vol 10 (22) ◽  
pp. 8057 ◽  
Author(s):  
Aiman Albatayneh ◽  
Dariusz Alterman ◽  
Adrian Page ◽  
Behdad Moghtaderi

Energy-efficient building design needs an accurate way to estimate temperature inside the building which facilitates the calculation of heating and cooling energy requirements in order to achieve appropriate thermal comfort for occupants. Sky temperature is an important factor for any building assessment tool which needs to be precisely determined for accurate estimation of the energy requirement. Many building simulation tools have been used to calculate building thermal performance such as Autodesk Computational Fluid Dynamics (CFD) software, which can be used to calculate building internal air temperature but requires sky temperature as a key input factor for the simulation. Real data obtained from real-sized house modules located at University of Newcastle, Australia (southern hemisphere), were used to find the impact of different sky temperatures on the building’s thermal performance using CFD simulation. Various sky temperatures were considered to determine the accurate response which aligns with a real trend of buildings’ internal air temperature. It was found that the internal air temperature in a building keeps either rising or decreasing if higher or lower sky temperature is chosen. This significantly decreases the accuracy of the simulation. It was found that using the right sky temperature values for each module, Cavity Brick Module (CB) Insulated Cavity Brick Module (InsCB), Insulated Brick Veneer Module (InsBV) and Insulated Reverse Brick Veneer Module (InsRBV), will result in 6.5%, 7.1%, 6.2% and 6.4% error correspondingly compared with the real data. These errors mainly refer to the simulation error. On the other hand using higher sky temperatures by +10 °C will significantly increase the simulation error to 16.5%, 17.5%, 17.1% and 16.8% and lower sky temperature by +10 °C will also increase the error to 19.3%, 22.6%, 21.9% and 19.1% for CB, InsCB, InsBV and InsRBV modules, respectively.


2020 ◽  
Vol 330 ◽  
pp. 01011
Author(s):  
Labouda Ba ◽  
Ikram El Abbassi ◽  
Cheikh S.E Kane ◽  
A-M Darcherif ◽  
Mamoudou Ndongo

Developing countries are facing population growth, which leads, on the one hand, to increased requirements for buildings and, on the other hand, to the depletion of fossil fuels along with exposure, of people living in those areas, to some detrimental consequences of climate change. Because of these factors, we propose approaches to control energy consumption in buildings. In some countries, the architectures adopted are not adequate to the environment and climate, resulting in discomfort in those buildings, in such circumstances, residents resort to the use of energy systems, such as heating, ventilation, and air conditioning, which leads to exorbitant electricity bills. Housing consumes 40% of the world's energy and is responsible for a third of greenhouse gas emissions. Optimizing energy needs in buildings is a solution to overcome these problems. For this purpose, there are solutions such as: the design of the building characterized by its shape and envelope, while using less energy-consuming equipment. For several years, the building materials sector has been developing with a particular focus on bio-source materials, which are generally materials with good thermal performance. In order to highlight the thermal performance of bio-source materials, we will study the case of Typha Australis which is a plant of the Typhaceae family that grows abundantly in an aquatic environment mainly in the Senegal River valley.Recent studies showed that Typha Australis has good thermal insulation properties. In order to determine the impact of Typha Australis on a building, a dynamic thermal simulation was carried out using the Trnsys software according to specific scenarios, the Typha was mixed with other local materials and used as a wall insulation panel, the result of the study shows that this fiber has allowed us to optimize energy consumption in a building. Mixing Typha with other materials (e. g. clay) is a promising solution for energy efficiency in buildings.


2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2355-2365
Author(s):  
Veliborka Bogdanovic ◽  
Dusan Randjelovic ◽  
Miomir Vasov ◽  
Marko Ignjatovic ◽  
Jelena Stevanovic

This paper analyzes the impact of Trombe wall construction on heating and cooling demands of building with form (rectangular single-store building of about one hundred square meters area) which is common for individual residential buildings in the Republic of Serbia. Trombe wall, as a representative of a passive solar design, was installed on the south wall of the building. Model of the building was made in the Google SketchUp software, while the results of energy performance were obtained using EnergyPlus and jEplus. Parameters of thermal comfort and climatic data for the area of city of Belgrade, Republic of Serbia, were taken into account. Coverage of the south fa?ade was varied, as well as the thickness of the thermal mass and orientation. Energy consumption of the object is discussed, based on obtained results of the analysis. According to comparative analysis of the above mentioned models it can be concluded that the application of the Trombe wall structure on south side may lead to savings of 33% on heating, but also the higher energy consumption for cooling. Total energy consumption on an annual basis is reduced by using this system.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5836
Author(s):  
Ali Mohammed AL-Dossary ◽  
Daeung Danny Kim

In Saudi Arabia, residential buildings are one of the major contributors to total energy consumption. Even though there are abundant natural resources, it is somewhat difficult to apply them to building designs, as design variables, due to slow progress and private issues in Saudi Arabia. Thus, the present study demonstrated the development of sustainable residential building design by examining the daylighting and energy performance with design variables. Focusing on the daylighting system, the design variables were chosen, including window-to-wall ratios (WWR), external shading devices, and types of glazing. The illuminance level by these design variables in a building was evaluated by using daylight metrics, such as spatial daylight autonomy and annual sunlight exposure. Moreover, the building energy consumption with these design variables was analyzed by using energy simulation. As a result, the daylighting was improved with the increase in WWRs and the tinted double glazing, while these design options can cause overheating in a residential building. Among types of glazing, the double pane windows with a low-E coating showed better energy performance. Based on the results, it is necessary to find the proper design variables that can balance the daylighting and energy performance in residential buildings in hot climates.


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